Fig. 1From: A mathematical approach to virus therapy of glioblastomasTwo circles representing the two propagation fronts of VSV and GBM. A front of tumor cells spreads radially (outer circle). After some time, viruses are inoculated at the center, and a virus front spreads (inner circle). If the inner circle expands faster than the outer one (c VSV >c GBM ), the viruses will eliminate the tumorBack to article page